Development of Facade Facing Ceramics with Self-Glazing Effect and Increased Energy Efficiency

The research presents the charge composition development on the basis of low-plasticity clay from the Vladimir region deposits for the production of ceramics for construction purposes. This low-plasticity clay is in low demand for ceramic production due to its poor durability, frost resistance and crack resistance resulted in products quality. To improve ceramics quality, it has been proposed to introduce trepel from the Vladimir region, boric acid and cullet into the charge. Trepel allows obtaining material fine-porous structure, which reduces thermal ceramics conductivity alongside maintaining its sufficient strength and frost resistance. The joined usage of cullet and boric acid provides liquid-phase sintering to form a vitreous phase, which serves as a binder of ceramic particles, fills large pores and voids in the material depth and provides self-glazing effect on the products surface. Simultaneously the fine-porous structure remains, since vitreous phase viscosity does not allow penetrating into small pores. As a result, the material strength increases, water absorption decreases and frost resistance increases, but self-glazing effect also allows creating a self-cleaning surface in the snow and rain, which is important for facade products. The application of the charge developed composition allows expanding the raw materials specification for the construction ceramics due to the low-plasticity clay and cullet usage for manufacturing high quality facing products that meet regulatory requirements for the outdoor facades cladding.